Theft-prevention structure for depositories

ABSTRACT

A depository having a structure which prevents unauthorized removal of items from the depository. The depository includes an enclosure having a hollow interior to which access may be had through a lower door which can only be opened in an authorized manner. The enclosure has an upper drop-in opening and an upper door movable between a closed position closing the drop-in opening and an open position also closing the drop-in opening. However the upper door has a receiving portion accessible when the upper door is in its open position for receiving an item to be placed in the enclosure, and the upper door drops the item into the hollow interior of the enclosure when the upper door is returned to its closed position. A blocking structure is provided at the rear of the upper door for blocking removal of items in the enclosure out through the upper drop-in opening thereof, and this blocking structure is mounted for movement away from a blocking position when engaged by an item falling from the receiving portion of the upper door down into the hollow interior of the enclosure. the upper door has a locking structure which coacts with the blocking structure to lock the latter against movement away from the blocking position whenever the upper door is displaced even through a small part of the way from its closed toward its open position. Also, the blocking structure coacts with the lock structure to prevent movement of the upper door toward its open position in the event that the blocking structure has been displaced in some way away from the blocking position.

United States Patent Hinohara et al.

[54] THEFT-PREVENTION STRUCTURE FOR DEPOSITORIES [7-2] Inventors: Kongo Hinohara; Tadashl Nishino, both of Hiroshima; Hlroshi Hands, Gion-machi, all of Japan [73] Assignee: Kabushiki Kaisha Kumahira Seisakusho, Hiroshima-shi, Japan [22] Filed: Nov. 20, 1970 [21] Appl. No.: 91,498

[30] Foreign Application Priority Data Feb. 6, 1970 Japan ..45/9987 [52] US. Cl. ..232/44 [51] Int. Cl ..E05g 1/00 [58] Field of Search ..232/44, 47, 49, 48, 45, 50, 232/51, 53, 54, 58, 28, 31

[5 6] References Cited UNITED STATES PATENTS 2,901,165 8/1959 Krug .232/44 555,948 3/1896 Harrison et al....... ..232/49 428,968 5/1890 Snead ..232/48 450,379 4/1891 Sinclaire... "232/51 625,819 5/1899 Warfield ..232/51 668,267 2/1901 Roy ..232/50 2,921,735 1/1960 Blauvelt ..232/44 l 5 1 Dec.5, 1972 Primary Examiner- Francis K. Zugel Attor ngy- Steinberg & Blake [5 7] ABSTRACT A depository having a structure which prevents unauthorized removal of items from the depository. The depository includes an enclosure having a hollow interior to which access may be had through a lower door which can only be opened in an authorized manner. The enclosure has an upper drop-in opening and an upper door movable between a closed position closing the drop-in opening and an open position also closing the drop-in opening. However the upper door has a receiving portion accessible when the upper door is in its open position for receiving an item to be placed in the enclosure, and the upper door drops the item into the hollow interior of the enclosure when the upper door is returned to its closed position. A blocking structure is provided at the rear of the upper door for blocking removal of items in the enclosure out through the upper drop-in opening thereof, and this blocking structure is mounted for movement away from a blocking position when engaged by an item falling from the receiving portion of the upper door down into the hollow interior of the enclosure. the upper door has a locking structure which coacts with the blocking structure to lock the latteragainst movement away from the blocking position whenever the upper door is displaced even through a small part of the way from its closed toward its open position. Also, the blocking structure coacts with the lock structure to prevent movement of the upper door toward its open position in the event that the blocking structure has been displaced in some way away from the blocking position.

10 Claims, 4 Drawing Figures PATENTED BEL 5 I972 SHEET 1 BF 2 THEFT-PREVENTION STRUCTURE FOR DEPOSITORIES BACKGROUND OF THE INVENTION The present invention relates to depositories.

In particular, the present invention relates to that type of depository which is provided with a drop-in opening through which articles may be dropped into the depository even when the latter is closed.

For example, banks have vaults into which items may be dropped even when the bank is closed, the items being dropped through a drop-in opening accessible to depositors when the bank is closed.

With depositories of the above general type it is customary to provide over a door which may be opened in an authorized manner only, a drop-in opening provided with a second door in the form of a swingable assembly which maintains the drop-in opening closed even when this upper door is displaced to an open position for receiving an item to be deposited. When the upper door is returned to its closed position the item placed on the door will drop into the enclosure.

Without resorting to special measures, it would be possible for a thief to remove items from the interior of the enclosure even though the drop-in opening is provided with adoor which keeps the opening closed even when the door is opened and which only permits an article to fall from the door into the enclosure when the upper door is returned to its closed position. For example, it is possible to insert a fishing hook carried by a fishing line through gaps around the upper door into the lower hollow interior of the enclosure to hook onto a cloth bag or the like in which money or other valuables are located, and then by carefully raising the hook through the fishing line attached thereto it is possible with suitable manipulation of the upper door to remove the article from the depository.

In order to prevent such thefts it is customary to provide such structures with blocking elements which extend across the drop-in opening to prevent items from being removed out of the enclosure through the drop-in opening thereof for example through the use of fishing gear as set forth above. However, in order to enable an item to fall into the hollow interior of the enclosure, such blocking elements must be free to swing away to a non-blocking position when engaged by a falling item. It is therefore possible with conventional structures of this type for a thief to insert a thin narrow flexible article such as a sheet or a strip of celluloid or other plastic in such a way that it is possible to manually hold the blocking structure away from the blocking position while an item is removed through the drop-in opening through manipulations along the lines set forth above.

A satisfactory solution to theft of items from depositories of this general type has not yet been provided.

SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a depository of the above general type with a structure which will reliably prevent theft of items from the depository.

In particular, it is an object of the present invention to provide a depository of the above type with a construction which will prevent movement of a blocking structure away from a blocking position when the upper door at the drop-in opening is displaced from its closed position.

Also, it is an object of the invention to provide blocking structure of the above type which will in addition function to prevent the upper door from being displaced toward the open position if it should happen that the blocking structure is displaced away from the blocking position.

In addition it is an object of the present invention to provide a structure of the above type which will reliably serve to prevent removal of items through the drop-in opening even if part of a blocking structure has been displaced to a non-blocking position.

Furthermore, it is an object of the invention to provide a structure of this type which is simple, relatively inexpensive, and at the same time rugged and highly reliable with along operating life assured.

According to the invention the depository is provided with an enclosure having a lower hollow interior for receiving items. A lower door means is provided for giving access to the hollow interior only in an authorized manner. The enclosure is formed with an upper drop-in opening and carries an upper door means movable from a closed to an open position for making accessible to a depositor a receiving portion of the upper door means on which an item to be deposited is placed. This upper door means in its closed position as well as in its open position maintains the drop-in opening closed, but when swung from its open to its closed position with an item on the receiving portion, the upper door means functions to drop the item down into the hollow interior of the enclosure. A blocking means is provided behind the upper door means at the drop-in opening to prevent items from being removed out of the enclosure through the drop-in opening. A mounting means mounts this blocking means for free movement away from its blocking position when engaged by items falling from the receiving portion of the upper door means down into the hollow interior of the enclosure. A lock means is carried by the upper door means for movement therewith, and this lock means locks the blocking means against movement away from its blocking position when the upper door means is displaced from its closed toward its open position, so that in this way if a thief should attempt to remove items from the hollow enclosure by manipulation of the upper door means and through operations along the lines set forth above, the lock means will reliably prevent displacement of the blocking means away from the blocking position so as to maintain the blocking means in a position preventing removal of items out of the enclosure. This blocking means also coacts with the lock means to prevent movement of the upper door means from its closed toward its open position if it should happen that the blocking means has been displaced away from the blocking position thereof.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a partly schematic longitudinal sectional elevation of a depository according to the invention taken in a vertical plane which is perpendicular to the closed doors of the depository;

FIG. 2 is a fragmentary sectional elevation, taken in the same plane as FIG. 1 but showing fragmentarily and at an enlarged scale, as compared to FIG. 1, the part of The dehumidifier film or coat is strongly bonded to the material of a container being dehydrated, so that no additional means or operations are required for securing said dehumidifier composition in said container.

The method of obtaining the present dehumidifying composition in the form of a film or coat comprises applying onto the inner surface of containers a suspension containing 100 parts by weight of zeolite having a humidity of 20-23 wt. percent, 45-280 parts by weight of a thermosetting resin, 120 parts by weight of an organic solvent intended for dissolving said resin, -45 parts by weight of a suitable plasticizer, and 085 parts by weight of a curing agent.

The suspension applied onto the inner surface of a container is maintained in the air at a temperature of from 5 to 80 C in order to remove the bulk of volatile components, followed by subjecting said suspension to heat treatment in vacuo at a residual pressure of not greater than mm Hg and at a temperature of from 150 to 180 C. Said heat treatment removes the last traces of volatile components, brings about binder polymerization and results in the formation of film or coat (layer) depending upon the amount of the suspension used, said film (coat) being characterized by a highly extended porous structure which is adhesively bonded to the coated surface and provides for the requisite kinetics of water vapor adsorption. The porous structure of a dehumidifying composition film is defined by the volume of primary pores in zeolite crystals and by the volume of secondary pores. The

volume of secondary pores depends primarily on the dispersity of zeolite crystals and binder (resin) particles, as well as on the nature of the binder used, and the type and density of zeolite crystal and binder particle packing.

The volume of secondary pores in the range of equivalent radii of from 291,000 to 31 A equals 0.044 cm lcm a significant portion of said volume (0.020 em /cm") being due to the pores in the equivalent radius range of from 98 to 3l An essential feature of the present dehumidifying composition is that it provides the possibility of controlling the kinetics of adsorption by varying the proportion of components of stock suspensions, so that the present dehumidifying composition can be used in devices and instruments of various types and sizes, the desired kinetics of moisture adsorption inside a given device (instrument being attained by selecting an appropriate ratio of suspension components. As compared to the known dehumidifying agents in the form of tablets or thickened silicone oil-based mixtures, the present dehumidifying composition in the form of a film or coat occupies a very small volume inside casings and has an insignificant weight. Said beneficial characteristics of the present dehumidifying composition make it eminently suited for use in conjunction with microminiaturized electronic instruments. The dehumidifying composition contained in an instrument cas- The present dehumidifying composition is employed without resorting to mechanical means for securing said composition in instrument (device) casings or to special-type equipment for introducing said composi tion into instrument (device) casings and is suitable for being introduced into casings (bulbs) of any shape or size at one and the same production section, the latter feature being highly advantageous for the simultaneous production of diverse types of semiconductor instruments. It is expedient to use the present dehumidifying composition irrespective of the scale or automation degree of production processes or when the manufacture of instrument casings and the assembly of finished semiconductor devices are carried out at different plants.

It follows from the foregoing that the present dehumidifying composition used in the form of a film or coat is commercially superior to the known dehumidifiers.

The following examples are illustrative of the manner of carrying out the invention but are not intended to limit the scope thereof.

EXAMPLE 1.

One hundred parts by weight of Type Na zeolite A (moisture content, 25 percent by weight; particle diameter, 4 me maximum) is mixed with parts by weight of epoxide resin (molecular weight, 370-450; epoxy group content, 18 percent) dissolved in l27 parts by weight of an organic solvent having the following composition, percent by weight: butyl acetate, 10; cellosolve (C H -OCH CH OH), 8; acetone, 7; butanol, 15; ethanol, 10, and toluene, 50. Dubutyl phthalate (plasticizer) is added to the stirred mixture in an amount of 5 parts by weight, followed by introducing 10 parts by weight of polyethylene polyamine (curing agent). The resulting mixture is thoroughly mixed to obtain a homogeneous suspension. The dehumidifying composition thus prepared is ready for use.

Use is made of a buret, an atomizer or a syringe to apply the composition on the inner surface of instrument metal casings (bulbs) having a volume of 0.25 cm From 10 to 12 mg of said composition is introduced in each bulb, followed by maintaining the bulbs with said composition applied thereonto for a period of 10-20 hours in the air at ambient temperature in order to remove the bulk of volatile components. Next the bulbs are placed in a vacuum drying cabinet, subjected to gradual heating to a temperature of C at a residual pressure of 0.1 mm Hg, and maintained at this temperature for a period of 3 hours. It is pertinent to gradually heat the composition in order to provide in the resultant film an access of zeolite micropores to the ambient atmosphere and to attain good adhesion of the film to the bulb surface. The resultant film displays heat stability up to a temperature of 200C in the air. The thus-treated bulbs are ready for use as sealing components of instruments or circuits.

Mechanical tests of the film under the conditions prescribed for testing transistors enclosed in bulbs are indicative of the absence of crumbling, dusting or cracking phenomena.

The film obtained by the procedure described herein before is capable of maintaining in the hermetically sealed volume of the bulb a low relative humidity in the temperature range of from 60 to +1 50C.

flexible resilient sheet such as a sheet of celluloid through the gap between the wall 3 and the wall so as to engage the blocking means and displace it away from the blocking position, thus releasing items for removal out through the drop-in opening 4. It is precisely this type of operation which is reliably prevented by the present invention.

With the present invention there is a lock means 8 in the form of an elongated lock bar connected by at least one connecting member 7 to the rear wall 3 of the upper door means 1. Thus in the illustrated example the elongated lock bar 8 of the lock means extends parallel to the shaft 11 and terminates in the pair of connecting members 7 which extend perpendicularly from the lock bar 8 up to the rear wall 3 to which these end connecting members 7 are fixed. These connecting members 7 are situated laterally beyond the series of blocking bodies 6, as is apparent from FIG. 4. Because the connecting members 7 are fixed to the wall 3, the locking bar 8 will necessarily describe part of a cylinder whose axis coincides with the axis of shaft 11 during swinging of the upper door means 1 between its open and closed positions. The lateral edges of the protective wall 15 are respectively formed with notches 16 to provide clearance for the pair of connecting members 7 during swinging of the upper door means 1. The edge of the bar 8 which is directed toward the blocking bodies 6, in the position of the part shown in FIG. 2, is formed with an elongated groove 23, for a purpose referred to below.

It is furthermore to be noted that each of the bodies 6, which are independently swingable about the rod 5, is formed along at least one and preferably both edges with the pointed projections 24 which are of the configuration of an acute angle, and it will be noted that the groove 23 also has the cross section of an acute angle. Moreover the bodies 6 terminate in the pointed free ends at their lower regions, as is apparent from FIGS. 2 and 3.

With this construction, even when the upper door means 1 is swung through a relatively short distance from the closed position of FIG. 2 toward the open position of FIG. 3, the locking means 8 will sweep up behind the blocking means preventing the bodies 6 thereof from being displaced away from their blocking positions. Thus, as soon as the top edge of the front wall 2 has been swung forwardly to a position which would be sufficient to give a thief the possibility of inserting a celluloid strip or sheet through the gap between the walls 14 and 15, the lock means 8 has already become situated behind the blocking means to prevent movement thereof away from the blocking position, and thus it is not possible for a thief to displace the blocking means away from its blocking position once the upper door means has been moved even through a short distance from the closed position toward the open position.

As long as the bodies 6 rest by their own weight on the stop bar 17 carried by the wall 15, the bar 8 will clear the bodies 6 to enable the upper door means to be swung to the open position shown in FIG. 3. However, if any one of the bodies 6 should be moved away from the blocking position, the projections 24 at the front or rear edge of such a body 6 or the pointed tip thereof will be received in the groove 23 so that the blocking means will now act through the lock means on the upper door means to prevent the latter from being displaced to the open position. Thus the blocking means and lock means have a mutual interaction. The lock means will prevent the blocking means from being displaced to a non-blocking position while the blocking means, if it should be displaced away from the blocking position, will coact with the lock means to prevent the upper door means 1 from being swung to its open position.

A further safety feature of the invention resides in the fact that there are a plurality of blocking bodies 6 each of which is freely movable independently of the others. Therefore if it should happen that a thief succeeds in swinging one or two or even three of the bodies 6 away from their blocking positions, the remaining bodies 6 will still remain in their blocking positions, preventing an article from being removed out of the enclosure 10 even if somehow a thief did succeed in working an item through suitable manipulation of fishing gear and the upper door means all the way up to the region of the blocking means. Thus, any blocking bodies 6 which are displaced away from their blocking positions will function to prevent the upper door means from being moved to its open position while any blocking bodies 6 which remain in their blocking position will prevent items from being removed. This action takes place even after a slight rotary movement of the upper door means from its closed toward its open position. While the projections 24 can be provided on at least one of the edges of each body 6, it is preferred to provide them on both edges. However, when the projections 24 are provided on only one edge, they are situated at the outer or right edge of each body 6, as viewed in FIGS. 2 and 3.

Thus, with the structure of the invention the depository is rendered theft-proof.

What is claimed is:

1. In a depository, an enclosure having a hollow interior for receiving deposited items, said enclosure having a lower door means through which access may be had to the hollow interior of said enclosure only when said lower door means is opened in an authorized manner, said enclosure being formed at an elevation higher than said lower door means with a drop-in opening through which items may be dropped into said enclosure, upper door means carried by said enclosure at said drop-in opening thereof for movement between a closed position closing said opening and an open position also closing said opening, said upper door means having a receiving portion accessible when said upper door means is in said open position thereof for receiving an item to be dropped into the hollow interior of said enclosure, said upper door means when returning to said closed position thereof dropping an item at said receiving portion into the hollow interior of said enclosure, blocking means carried by said enclosure in the interior thereof behind said upper door means for blocking, when said blocking means is in a first blocking position, movement of items out of the hollow interior of said enclosure through said drop-in opening, mounting means carried by said enclosure and mounting said blocking means for movement away from said first blocking position by items falling from said receiving portion of said upper door means downwardly into 7 8 and exhibits the requisite kinetics of water vapor ad- 8. A hemetically scalable container for providing sorptiona moisture free environment for enclosing moisture enclosure for Providing a moisture-free sensitive equipment having at least some portion of Vifonmenl comprising a container for said environ its inner surface coated with a film of the dehumidifyment, having at least some portion of its inner surface 5 ing compasition f claim L coated with a film of the desiccant composition of claim 1.

Y 47 762100.901 coll/602 1011 a; r 1 a l.

upper door means is moved from said closed toward said open position thereof, said lock means including an elongated locking bar extending parallel to the horizontal axis of swinging of said upper door means and a connecting member fixed to said locking bar and said rear wall of said door means for connecting said bar to said door means for swinging movement therewith.

7. The combination of claim 6 and wherein said blocking body has projections for engaging said locking bar to prevent movement of said upper door means to said open position thereof if said blocking body is displaced away from said blocking position.

8. The combination of claim 7 and wherein said blocking body is in the form of an elongated arcuate member extending along a circle concentric with the turning axis of said upper door means, said mounting means pivotally supporting said blocking body for free swinging movement due to its own weight about an axis parallel to the turning axis of said upper door means to a blocking position where said blocking body is located just inside of a cylinder described by said bar during turning of said upper door means from said closed to said open position thereof.

9. The combination of claim 8 and wherein a protective wall which forms part of a cylinder is situated between said blocking body and said upper door means and forms at least part of a means limiting swinging movement of said blocking body by its own weight to determine the blocking position of said blocking body.

10. The combination of claim 9 and wherein a plurality of said blocking bodies are distributed across said drop-in opening behind said upper door means and said mounting means being in the form of an elongated pivot rod independently supporting said plurality of blocking bodies for free swinging movement each independently of the others. 

1. In a depository, an enclosure having a hollow interior for receiving deposited items, said enclosure having a lower door means through which access may be had to the hollow interior of said enclosure only when said lower door means is opened in an authorized manner, said enclosure being formed at an elevation higher than said lower door means with a drop-in opening through which items may be dropped into said enclosure, upper door means carried by said enclosure at said drop-in opening thereof for movement between a closed position closing said opening and an open position also closing said opening, said upper door means having a receiving portion accessible when said upper door means is in said open position thereof for receiving an item to be dropped into the hollow interior of said enclosure, said upper door means when returning to said closed position thereof dropping an item at said receiving portion into the hollow interior of said enclosure, blocking means carried by said enclosure in the interior thereof behind said upper door means for blocking, when said blocking means is in a first blocking position, movement of items out of the hollow interior of said enclosure through said drop-in opening, mounting means carried by said enclosure and mounting said blocking means for movement away from said first blocking position by items falling from said receiving portion of said upper door means downwardly into the hollow interior of said enclosure after said door means is returned to said closed portion thereof, and lock means carried by said upper door means and coacting with said blocking means when the latter is in its first blocking position for preventing movement of the latter away from said first blocking position when said door means is displaced from said closed to said open position, said blocking means having a second blocking position displaced slightly away from said first blocking position and having a lock-engaging portion situated in the path of movement of said lock means on said upper door means when the latter is displaced from said closed toward said open position thereof for preventing movement of said upper door means from said closed to said open position thereof in the event that said blocking means is not initially in said first blocking position thereof.
 2. The combination of claim 1 and wherein said lock means coacts with said blocking means to prevent movement thereof away from said blocking position at an initial part of the movement of said upper door means from said closed toward said open position, with said lock means releasing said blocking means for movement away from said blocking position only when said upper door means is in the region of said closed position thereof.
 3. The combination of claim 2 and wherein said blocking means coacts with said lock means for preventing movement of said upper door means beyond an initial small portion of the way from said closed to said open position thereof and to an extent sufficient to give access to said receiving portion of said upper door means when said blocking means is displaced away from said blocking position thereof.
 4. The combination of claim 3 and wherein said enclosure supports said upper door means for swinging movement about a substantially horizontal axis between said closed and open positions, said upper door means having a front wall closing said drop-in opening when said upper door means is in said closed position thereof and a rear wall closing said drop-in opening when said upper door means is in said open position thereof, said receiving portion being situated between said front and rear walls, and said lock means being carried by said rear wall of said upper door means for swinging movement therewith.
 5. The combination of claim 4 and wherein said blocking means includes at least one swingable blocking body situated behind said door means and having a blocking position situated in a path of falling movement of an item dropping from said receiving portion into said enclosure, said mounting means mounting said blocking body for free swinging movement away from said blocking position when engaged by a falling item, and said lock means being moved behind said blocking body during movement of said upper door means from said closed to said open position thereof to prevent said blocking body from swinging away from said blocking position when said upper door means is moved from said closed toward said open position thereof.
 6. In a depository, an enclosure having a hollow interior for receiving deposited items, said enclosure having a lower door means through which access may be had to the hollow interior of said enclosure only when said lower door means is opened in an authorized manner, said enclosure being formed at an elevation higher than said lower door means with a drop-in opening through which items may be dropped into said enclosure, upper door means carried by said enclosure at said drop-in opening thereof for movement between a closed position closing said opening and an open position also closing said opening, said upper door means having a receiving portion accessible when said upper door means is in said open position thereof for receiving an item to be dropped into the hollow interior of said enclosure, said upper door means when returning to said closed position thereof dropping an item at said receiving portion into the hollow interior of said enclosure, blocking means carried by said enclosure in the interior thereof behind said upper door means for blocking movement of items out of the hollow interior of said enclosure through said drop-in opening, mounting means carried by said enclosure and mounting said blocking means for movement away from a blocking position by items falling from said receiving portion of said upper door means downwardly into the hollow interior of said enclosure after said door means is returned to said closed position thereof, and lock means carried by said upper door means and coacting with said blocking means for preventing movement of the latter away from said blocking position when said door means is displaced from said closed to said open position, said lock means coacting with said blocking means to prevent movement thereof away from said blocking position at an initial part of the movement of said upper door means from said closed toward said open position, with said lock means releasing said blocking means for movement away from said blocking position only when said upper door means is in the region of said closed position thereof, said blocking means coacting with said lock means for preventing movement of said upper door means beyond an initial small portion of the way from said closed to said open position thereof and to an extent sufficient to give access to said receiving portion of said upper door means when said blocking means is displaced away from said blocking position thereof, said enclosure supporting said upper door means for swinging movement about a substantially horizontal axis between said closed and open positions, said upper door means having a front wall closing said drop-in opening when said upper door means is in said closed position theReof and a rear wall closing said drop-in opening when said upper door means is in said open position thereof, said receiving portion being situated between said front and rear walls, and said lock means being carried by said rear wall of said upper door means for swinging movement therewith, said blocking means including at least one swingable blocking body situated behind said door means and having a blocking position situated in a path of falling movement of an item dropping from said receiving portion into said enclosure, said mounting means mounting said blocking body for free swinging movement away from said blocking position when engaged by a falling item, and said lock means being moved behind said blocking body during movement of said upper door means from said closed to said open position thereof to prevent said blocking body from swinging away from said blocking position when said upper door means is moved from said closed toward said open position thereof, said lock means including an elongated locking bar extending parallel to the horizontal axis of swinging of said upper door means and a connecting member fixed to said locking bar and said rear wall of said door means for connecting said bar to said door means for swinging movement therewith.
 7. The combination of claim 6 and wherein said blocking body has projections for engaging said locking bar to prevent movement of said upper door means to said open position thereof if said blocking body is displaced away from said blocking position.
 8. The combination of claim 7 and wherein said blocking body is in the form of an elongated arcuate member extending along a circle concentric with the turning axis of said upper door means, said mounting means pivotally supporting said blocking body for free swinging movement due to its own weight about an axis parallel to the turning axis of said upper door means to a blocking position where said blocking body is located just inside of a cylinder described by said bar during turning of said upper door means from said closed to said open position thereof.
 9. The combination of claim 8 and wherein a protective wall which forms part of a cylinder is situated between said blocking body and said upper door means and forms at least part of a means limiting swinging movement of said blocking body by its own weight to determine the blocking position of said blocking body.
 10. The combination of claim 9 and wherein a plurality of said blocking bodies are distributed across said drop-in opening behind said upper door means and said mounting means being in the form of an elongated pivot rod independently supporting said plurality of blocking bodies for free swinging movement each independently of the others. 